220 plug type, 3 prong vs. 4 prong ? - DoItYourself Electrical - AC & DC - 220 plug type, 3 prong vs. 4 prong ? - I was trying to assist a friend with a 220v water pump at a lakeside campsite. The plug on the pump is a 220 volt 3 prong plug, but How to install a 220 Volt 4 wire outlet - AskmeDIY 4 Wire Outlet The wire. If you were installing a four wire 220 outlet chances are it’s for a stove/oven. Now, this could be either 40 or 50 amp. So either #6 or # 8 wire. These wires are a lot harder to handle and thread through the walls and ceilings and generally cost a 3 Wire 220V Wiring Diagram - Wiring Diagram And Schematic Description: How To Wire 240 Volt Outlets And Plugs within 3 Wire 220V Wiring Diagram, image size 750 X 328 px, and to view image details please click the image. Here is a picture gallery about 3 wire 220v wiring diagram complete with the description of the image, please find the image you need.